The AMSR-2 sea ice concentration product (OSI-408)
As part of the Continuous Development and Operation Phase (CDOP-2), a sea ice concentration product “complementary to the SSMIS global sea ice concentration product (OSI-401-b), which is in operation and has been freely available for many years“ has been added to the Ocean and Sea Ice Satellite Application Facility's (OSI SAF's) product portfolio. The product utilises the AMSR-2 satellite microwave radiometer data.
The ASMR-2 instrument is a dual-polarized, conically scanning, microwave radiometer. The conically scanning radiometer has a constant incidence angle of ~55 degree on the ground and a swath width of ~1450 Km. The channels used in the computation of ice concentration fields are 18.7v, 36.5v, 36.5h, 89.0v and 89.0h.
OSI-408 is comprised of two ice concentration fields: one produced with the TUD algorithm and another using with the OSI SAF Hybrid Dynamic algorithm. The OSI SAF Hybrid Dynamic product is the primary product and is recommend for operational systems. The TUD product is experimental and is more susceptible to noise.
How should I cite this dataset?
This dataset shall be referred to as the AMSR-2 sea ice concentration product of the EUMETSAT Ocean and Sea Ice Satellite Application Facility (OSI SAF, www.osi-saf.org).
Which satellite sensors are processed?
The brightness temperatures at 19v, 37v, 37h, 89v and 89h measured by the conically scanning ASMR-2.
What is the spatial resolution of this product?
For the main product, the spatial resolution (3-dB footprint size) of the 19 GHz (lowest resolution) channel used in the ice concentration ice concentration algorithm is approximately 18 km; this is comparable to the 56 km resolution of the 19GHz channel used for the SSMIS product. The spatial resolution is, therefore, approximately three times greater for AMSR-2 than the SSMIS product. The product is delivered on a 10 km grid.
For the TUD product, the spatial resolution is not specified; however, since it uses a combination of the four channels it is between 18 and 4.5 km (the lowest and highest spatial resolution channels).
What is the time-span of this product?
One day (24 hours).
What are the contents of the product?
The product consists of these major fields:
- Sea ice concentration. Indicates the fraction of a given ocean grid point covered by ice. It is given as a decimal number, between the range of 0-100%.
- Uncertainties. The algorithm uncertainty, the smearing uncertainty and the resulting total uncertainty of each sea ice concentration grid cell value are given in three separate fields. These absolute uncertainties are given in percentages, between a range of 0-100%.
- Confidence level. The confidence level is based on the daily standard deviation within each gridcell, and defined using the calculated standard deviation (SD) of the sea ice concentration.
Today's product file is empty or has large data gaps, what happened?
There are two possible reasons for missing data:
- In case of interrupted data link with the satellite operating centres, no input swath data are available for processing of sea ice drift data inside the time constraints, resulting in an empty grid.
- The data point values are outside of model range.
Where can I find the ice concentration for Arctic/Antarctic regions?
The product is global and covers sea ice and ice shelves in the Arctic and the Antarctic.
I do not fancy NetCDF, do you have other formats?
The processing chain is currently only producing NetCDF files. Please let us know (contact) if you need another format.
Validation of OSISAF can be found in the product specific validation report, also referred to in Documentation and links, below.
The following documentation is available, further describing the OSI-408 AMSR2 sea ice concentration product.
Quicklooks are available here.